Spouses Silos vs. Philippine National Bank

Escalation clauses in loan agreements that grant the lender unilateral and exclusive power to fix or modify interest rates based on subjective or arbitrary criteria (such as internal bank policy, profitability, or cost of funds), without the borrower's prior written consent, are void for violating Article 1308 of the Civil Code on the mutuality of contracts.

Spouses Eduardo and Lydia Silos, engaged in the retail business, obtained a revolving credit line from PNB beginning in 1987, secured by real estate mortgages over two parcels of land in Kalibo, Aklan. The credit line was progressively increased to ₱2.5 million by 1989. The loan documents executed by the parties contained provisions allowing PNB to unilaterally modify interest rates depending on its future policies, a practice previously proscribed by the Court in similar cases involving the same bank.

• The Credit Line and Mortgage: In August 1987, petitioners secured a ₱150,000 revolving credit line from PNB, constituting a Real Estate Mortgage over a 370-sq.m. lot (TCT T-14250). The line was increased to ₱1.8 million in July 1988 and to ₱2.5 million in July 1989, with an additional mortgage over a 134-sq.m. lot (TCT T-16208).
• The 1989 Credit Agreement and Promissory Notes: The July 1989 Credit Agreement contained a stipulation allowing PNB to modify the interest rate "depending on whatever policy the Bank may adopt in the future" without notice. The eight Promissory Notes issued thereunder granted PNB the right to increase rates "within the limits allowed by law." Petitioner Lydia Silos testified that the interest rate portions were left blank for PNB to fill, which the bank did at rates escalating from 19.5% to 32%.
• The 1991 Amendment and Subsequent Notes: An August 1991 Amendment stipulated interest at the "prime rate plus applicable spread" determined by PNB. Petitioners issued 18 more Promissory Notes (9th to 26th) under this amendment, also signed in blank. The 9th to 17th notes allowed PNB to raise rates without notice; the 18th to 26th notes (including the final PN 9707237 dated July 30, 1997) allowed modification with prior notice and granted petitioners an option to prepay without penalty if they disagreed with the rate.
• Default and Foreclosure: Petitioners paid interest religiously from 1989 to 1997. However, they defaulted on PN 9707237 (₱2.5 million principal, 25% interest, 24% penalty) due in October 1997. PNB foreclosed the mortgages on January 14, 1999, purchasing the properties for ₱4,324,172.96.
• The Complaint: On March 24, 2000, petitioners filed suit seeking annulment of the foreclosure, alleging that the interest rate provisions were void for lack of mutuality, that they had overpaid, and that penalties were not secured by the mortgage.

• Void Escalation Clauses: The interest rate provisions in the Credit Agreements and Promissory Notes, which allowed PNB to unilaterally fix rates based on arbitrary criteria (bank policy, profitability, cost of funds), violated Article 1308 of the Civil Code on mutuality of contracts and were contrary to public policy.
• Lack of Consent: The promissory notes were signed in blank; interest rates were filled in later by PNB without prior consultation or agreement, violating the requirement under Article 1956 that interest be expressly stipulated in writing.
• Inapplicability of Estoppel: No estoppel could arise from their payment of illegal interest rates, as estoppel cannot be predicated on an illegal act.
• Exclusion of Penalties: The Real Estate Mortgage agreements did not specify penalties as part of the secured amount; thus, the ₱581,666.66 penalty under PN 9707237 could not be included in the foreclosure amount, citing Philippine Bank of Communications v. Court of Appeals.
• Attorney's Fees: The 10% attorney's fees were excessive; the trial court's reduction to 1% was proper given the minimal work involved in an extrajudicial foreclosure.

• Validity of Escalation Clauses: The clauses contained both escalation and de-escalation provisions, making them valid under P.D. No. 1684 and CB Circular 905. The increases were mutually agreed upon, evidenced by petitioners' continuous payment without protest for years, creating estoppel.
• Signing in Blank: The claim that documents were signed in blank was never raised in the trial court and was self-serving; the documents were presumed regular.
• Penalty Inclusion: The mortgage's "all-inclusive clause" ("and other obligations owing by the mortgagor to the mortgagee") covered the penalty, which was a normal banking practice to ensure performance.
• Attorney's Fees: The 10% rate was reasonable and authorized by the Real Estate Mortgage agreement; the CA correctly restored it.

• Validity of Interest Rate Provisions: Whether the interest rate provisions in the Credit Agreements and Promissory Notes, granting PNB unilateral power to fix rates, are void for violating the principle of mutuality of contracts.
• Applicability of Estoppel: Whether petitioners are estopped from questioning the interest rates by virtue of their prior payments without objection.
• Secured Amount: Whether the penalty charge is included in the amount secured by the Real Estate Mortgage.
• Attorney's Fees: Whether the award of 10% attorney's fees was proper notwithstanding the trial court's reduction to 1%.

• Validity of Interest Rate Provisions: The escalation clauses were declared null and void. Provisions allowing PNB to modify interest rates "depending on whatever policy it may adopt in the future" or based on "prime rate plus applicable spread" determined solely by the bank, without reference to an external standard or mutual agreement, violate Article 1308 of the Civil Code. Such clauses render the contract a contract of adhesion, negating mutuality.
• Truth in Lending Act: The practice of requiring petitioners to sign blank promissory notes violated Republic Act No. 3765 (Truth in Lending Act), which mandates disclosure of the full cost of credit prior to consummation.
• Applicability of Estoppel: Estoppel does not apply to illegal acts. The unilateral imposition of interest rates was illegal; thus, petitioners' payments did not ratify the void provisions.
• Interest Rate Application: The 2nd to 26th Promissory Notes are subject to interest at 12% per annum (until June 30, 2013) and 6% per annum (from July 1, 2013), in lieu of the void stipulated rates. Excess payments made above these rates shall be applied to the principal.
• Secured Amount: The penalty charge was excluded from the secured amount. A mortgage being an accessory contract, its scope is determined strictly by its terms; the phrase "other obligations" cannot be construed to include penalties when the mortgage is already tainted as a contract of adhesion.
• Attorney's Fees: The Court of Appeals erred in restoring the 10% attorney's fees. An appellee who does not appeal cannot obtain affirmative relief other than that granted in the decision below; the trial court's award of 1% stands.

• Mutuality of Contracts (Article 1308, Civil Code) — A contract must bind both parties; its validity or compliance cannot be left to the will of one. Any modification, particularly of a principal condition like the interest rate, requires mutual assent. A stipulation granting one party exclusive power to fix a contractual term is void.
• Escalation Clauses — While not inherently illegal, escalation clauses must be based on reasonable and valid standards (e.g., changes in law or Monetary Board regulations) and require mutual agreement for any adjustment. Clauses based solely on the lender's internal policy or subjective criteria are void.
• Contracts of Adhesion — Contracts prepared by one party (typically the stronger party, like a bank) and presented to the other on a "take it or leave it" basis are strictly construed against the drafter. Any ambiguity is resolved in favor of the weaker party.
• Truth in Lending Act (Republic Act No. 3765) — Creditors must furnish borrowers with a clear written disclosure statement of the full cost of credit (including interest and other charges) prior to the consummation of the transaction. Failure to do so renders the offending stipulations unenforceable.
• Solutio Indebiti — If accounting reveals that petitioners overpaid their obligation (principal + legal interest), the excess must be returned with legal interest, and the foreclosure shall be deemed void for lack of secured debt.

• "In loan agreements, it cannot be denied that the rate of interest is a principal condition, if not the most important component. Thus, any modification thereof must be mutually agreed upon; otherwise, it has no binding effect." — Establishes the centrality of interest rate mutuality.
• "A contract containing a condition which makes its fulfillment dependent exclusively upon the uncontrolled will of one of the contracting parties, is void... Hence, even assuming that the... loan agreement... gave the PNB a license... to increase the interest rate at will... that license would have been null and void for being violative of the principle of mutuality essential in contracts." — Citing PNB v. CA (1991), reaffirming the voidness of potestative conditions in contracts.
• "Estoppel cannot be predicated on an illegal act. As between the parties to a contract, validity cannot be given to it by estoppel if it is prohibited by law or is against public policy." — On the inapplicability of estoppel to validate void interest rate provisions.
• "Premium may not be placed upon a stipulation in a contract which grants one party the right to choose whether to continue with or withdraw from the agreement if it discovers that what the other party has been doing all along is improper or illegal." — Rejecting the "option to prepay" clause as a cure for unilateral rate fixing.

• Philippine National Bank v. Court of Appeals, 273 Phil. 789 (1991) — Controlling precedent establishing that unilateral escalation clauses violate Article 1308.
• Spouses Almeda v. Court of Appeals, 326 Phil. 309 (1996) — Reiterated the voidness of PNB's escalation clauses and the requirement for written agreement on interest rate changes.
• Philippine National Bank v. Court of Appeals, G.R. No. 107569 (1994) — Affirmed that de-escalation clauses alone do not cure the one-sidedness of unilateral escalation clauses; mutual consent is required.
• Philippine Bank of Communications v. Court of Appeals, 323 Phil. 297 (1996) — Held that penalty charges do not belong to the species of obligations secured by a real estate mortgage unless explicitly included.
• United Coconut Planters Bank v. Spouses Beluso, 557 Phil. 326 (2007) — Applied the Truth in Lending Act to void unilateral interest rate fixing and emphasized that disclosure must be prior to consummation.
• New Sampaguita Builders Construction, Inc. v. Philippine National Bank, 479 Phil. 483 (2004) — Courts have authority to strike down provisions granting lenders unrestrained power to increase interest rates.

• Article 1308, Civil Code — The contract must bind both contracting parties; its validity or compliance cannot be left to the will of one of them.
• Article 1956, Civil Code — No interest shall be due unless it has been expressly stipulated in writing.
• Article 1226, Civil Code — Penalty clauses; definition and purpose.
• Republic Act No. 3765 (Truth in Lending Act), Section 4 — Mandates prior written disclosure of finance charges and interest rates.
• Presidential Decree No. 1684 — Amended the Usury Law to allow escalation clauses only if coupled with de-escalation clauses and subject to mutual agreement.
• Central Bank Circular No. 905 — Removed interest rate ceilings but did not authorize unilateral fixing by banks.

Antonio T. Carpio (Chairperson), Teresita J. Leonardo-De Castro, Jose Portugal Perez, Estela M. Perlas-Bernabe.